Electrical relay



Dec. 20, 1927. 1,653,384

G. W. BAUGHMAN ELECTRICAL RELAY Filed Oct. 4, 1924 52 3g 7 25 25 L L LFig, 5

I l i INVENTOR.

59 QZ-W Patented Dec. 20, 1927.

UNITED STATES PATENT OFFICE.

GEORGE W. BAUG-HMAN, OF EDGEWOOD BOROUGH, PENNSYLVANIA, ASSIGNOR TO THEUNION SWITCH 8:7 SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORA-TION OF PENNSYLVANIA.

ELECTRICAL RELAY.

Application filed October 4, 1924. Serial No. 741,752.

My invention relates to electrical relays, and particularly to relays ofthe alternating current type responsive selectively to current of onefrequency but not to current of another frequency.

I will describe one form of relay embodying my invention, and will thenpoint out the novel features thereof in claims.

In the accompanying drawing, Fig. 1 is a plan view showing one form ofrelay embodying my invention and is also a dlagrammatic view showing oneform of apparatus with which the relay may be used. Fig. 2 is a viewshowing in side elevation the relay illustrated in Fig. 1. Fig 3 is asectional view on the line III-III of Fig. 1. Fig. 4

is a sectional vieW on the line IVIV of Fig.

2. Fig. 5 is a sectional view on the line V-V of Fig. 1.

Similar reference characters refer to 811111-- lar parts in each of theseveral views. 4

Referring to the drawing, the relay, which is designated as a whole bythe reference character R, comprises a magnetizable core 2 preferably oflaminated soft iron, which core is provided with two paths for magneticflux. One of these paths includes a pair of pole pieces 3 and 3separated by an air gap 24, whereas the other path comprises a pair ofpole pieces 5 and 5 separated by an air gap 6.

The relay is provided with two windings 8 and 9. The winding 8 islocated on a cross piece 28 forming part of the main body 5 of the core2 of the relay, so that the mag- .netic fiux created by this windingtends to flow through the two paths of pole pieces. The other winding 9is of the strap type, that is, it comprises a single strap ofelectroconductive. material, and this winding is mounted on the polepieces 3, 3 5 and 5*, as illustrated in Figs. 3, 4E and 5. Toaccommodate this winding each pole piece is slotted, as indicated at 25and 25 in Fig. 5.

The winding 9 is in the form of a letter S on pole pieces 3 and 5, asillustrated in Fig. 3, whereas on each pole piece 3 and 5 this windingmerely passes through the slot 25 Referring particularly to Fig. 5, itw1ll be observed that the winding 9 when supplied with alternatingcurrent creates a magnetic flux which flows in pole pieces 5 and 5 inthe path indicated by the arrows. This winding creates flux which flowsin the same manner in. pole pieces 3 and 3. If the alternating currentssupplied to the two windings 8 and 9 are of the same frequency but aredisplaced in phase, a shifting magnetic field will be created in eachair gap 4 and 6, the direction of shift on the air gaps being the same;that is, if the magnetic field in either air gap shifts upwardly, themagnetic field in the other air gap will alsoshift upwardly, and viceversa.

As shown in the drawing, the area of each pole piece 3 and 3 is smallerthan the area of each pole piece 5 and 5 It follows that unless othermeans were provided the magnetic field in air gap 6 would be strongerthan the magnetic field in air gap 4. Pole pieces 5 and 5 however, areprovided with closed conductors 7 and 7, respectively, as illustrated inFigs. 1 and 5, the effect of which is to increase the reluctance offeredto fluxes passing through air gap 6.

The relay is provided with a movable member which is acted upon by theshifting magnetic fields in the air gaps at and 6. In the form hereshown, this member is a vane 10 of non-magnetizable electro-conductivematerial, such as aluminum, which vane is mounted on a shaft 11. Thevane 10 is so disposed as to be oppositely affected by the shiftingfields in the two air gaps, and inasmuch as these fields both shift inthe same direction, the vane is mounted with its pivotal point betweentwo pairs of pole pieces. It follows that the shiftingfield in air gap 4will tend to move the vane in one direction, such for example, as incounter-clockwise direction, whereas the shifting field in the air gap 6will tend to move the vane in the other direction, such, for example, asin clockwise direction. The vane 10 is biased to one posi tion by anysuitable means, such, for example, as a counterweight 14, and this vanecontrols a contact 13 in such manner that when the vane occupies theposition to which it is biased by the counterweight this contact isopen, whereas, when the vane is shifted in counter-clockwise directionfrom such biased position, the contact is closed. As here shown, contact13 is operatively connected with an arm 12 fixed to the shaft 11 onwhich the vane is mounted.

The parts of the relay are so designed and adjusted that when thewindings 8 and 9 are supplied with alternating current of a givenfrequency the shifting magnetic fields in the air gaps 4: and 6 exertequal torque on the vane 10, so that contact 13 remains open. hen thecurrent supplied to the relay windings are of a different frequency,however, such, for example, as a higher frequency, the closed conductors7 and 7 reduce the amount of flux in the pole pieces and 5 and increasethe amount of flux in pole pieces 3 and 8, so that the torque exerted onthe vane 10 by the shifting magnetic field in air gap 4 is greater thanthe torque exerted on this vane by the shifting magnetic field in airgap 6. The vane 10 then moves in counter-clockwise direction, as viewedin Fig. 2, so that it closes contact 13.

Relays embodying my invention are particularly well adapted for use inrailway signaling systems, such, for example, as the system illustrateddiagrammatically in Fig. 1. Referring to this view, the referencecharacters and 15 designate the track rails of a railway, which railsare divided by insulated joints 16 to form an insulated track sectionAB. These rails are supplied with alternating propulsion current from agenerator G the terminals of which are connected with the rails throughbalanced bonds 27. The rails are provided, as usual, with bonds 26 toconduct the propulsion current around the insulated joints 16. Tracksection A-B is provided with a track circuit which is constantlysupplied with alternating signalingcurrent from a generator G throughthe medium of line wires 19 and 19, which wires are connected across therails of the section by wires 20 and 20*. lVinding 8 of relay R is alsoconnected across the rails of section AB by wires 17 and 18, and winding9 is constantly supplied with alternating current from the generator Gthrough a transformer T, the secondary of which is connected with thewinding 9, and the primary of which is connected with wires ,19 and 19tl'n'ough the medium of wires 21 and 21. Section A Bis provided with asignal. S which is controlled by a circuit passing from wire 19, throughwire 22, operating mechanism of signal S, wire 28, contact 13 of relayR, and wire 24 to line wire 19' The propulsion current supplied bygenerator G and the signaling current supplied by generator G differ infrequency; for example, th propulsion frequency may be 25 cycles persecond, and the signaling frequency may be cycles per second. The relayR is so designed and proportioned that when 60 cycle current issuppliedto both of the windings 8 and 9 a torque is created on the vane10 tending to shift this vane in counter-clockwise direction as viewedin Fig.2, thcrebyclosing contact 13 and cansing signal S to indicateproceed. If, how ever, current of the propulsion frequency should besupplied to both windings 8 and 9 due to any defect'intheapparatus,theeffect of this current would be to equalize the torquesexerted on vane 10 by the shifting magnetic fields in air gaps tandlflsothat this vane .would move to or remain in its biased position whereincontact 13 is open, sothat signal. S would indicate stop.

As shown in Fig. 1, section Al3 is occupiedby a train 'G,'the wheels andaxles of which shunt the signaling current away from winding 8. lVinding8 being -de-enerized, there are no shifting magnetic fields in the airgaps 4 and 6, so the vane 10 is in the biased position wherein contact12-3 is open and signal S indicates stop. lVhen the train C passes outof section rr-l3, signaling current will'be supplied to winding and sothe relay will be actuated to close contact 13, whereupon signal S willmove to the proceed position.

Although I have herein shown and described only one form of relayen'il'iodying my invention, it is understoodthat various changes andmodifications may be made therein within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having'thus described my invention, what I claim is:

1. A relay comprising a first operating winding, a core for said windinghaving two paths for the flux created by the winding, each pathincluding a pair of pole pieces separated by an air gap, asecondoperating winding located wholly on said two pairs of pole pieces, andarranged to receive alternating current from a source outside-oil the.relay, and a movable member mounted to be oppositely affected by thefluxes traversing said two air gaps.

2. A relay comprising a first winding, a core for said windinghaving twopaths for the flux created-by the winding, onepath including a inst pairof pole pieces of .relativcly small area separated by an airgap and theother path including a second pair of pole pieces of relatively largearea sep arated by an air gap, a second winding associated with said twopairs of pole pieces, closed conductors associated with the pole piecesof said second pair whereby the distribution of flux in saidtwo air gapsdue to current in each winding varies with variations in the frequencyof the current supplied to the winding, and a movable menr ber mountedto be oppositelyaffected bythe fluxes traversing said two airgaps.

3. A relay comprising a first winding, a core for said winding havingtwo paths for thefiux created by the winding, each path including a pairof pole pieces separated by an air gap, a second winding associated withsaid two pairs of pole pieces, closed conductors associated with thepole pieces of one pair but not with the other whereby the distributionof flux in said two air gaps due to current in each winding varies withvariations in the frequency of the current supplied to the winding, anda movable member mounted to be oppositely affected by the fluxestraversing said two air gaps.

4. A relay comprising a core having two paths for the flow of magneticflux, each path including a pair of pole pieces separated by an air gap,two windings associated with said core whereby when said windings aresupplied with currents differing in phase a shifting magnetic field iscreated in each air gap, closed conductors associated with the polepieces of one pair but not with the other whereby the distribu tion offlux in said two air gaps due to current in each winding varies withvariations in the frequency of the current supplied to the winding, anda movable member mounted to be oppositely affected by the shiftingmagnetic fields in said two air gaps.

5; A relay comprising a core having two paths for the flow of magneticflux, one path including a first pair of pole pieces of relatively smallarea separated by an air gap and the other path including a second pairof pole pieces of relatively large area separated by an air gap, twowindings as sociated with said core whereby when said windings aresupplied with alternating currents differing in phase a shiftingmagnetic field is created in each air gap, closed conductors associatedwith the second pair of pole pieces but not with the first whereby thedistribution of flux in said two air gaps due to current in eachwindingvaries with variations in the frequency of the current supplied to thewinding, and a movable member to be oppositely affected by the shiftingmagnetic fields in said two air gaps.

In testimony whereof I aifix my signature.

GEORGE W. BAUGHMAN.

